DEFINITION OF PARK TRANSFORM EXTENSIONS F OR THE CONTROL OF SURFACE-MOUNTED PERMANENT-MAGNET SYNCHRONOUS MOTORS

The high performance controls of surface-mounted permanent-magnet sync hronous motors are based on the use of the Park transformation. This s tate transformation offers certain advantages, among which, the fact t hat, in this new reference frame, the electromagnetic torque is direct ly an image of the quadrature (''q'') component of the stater current. This result applies only to the machines with sinusoidal flux distrib ution. We propose in this paper extensions of the Park's transformatio n to the machines with non-sinusoidal flux distribution. Two different versions are proposed and compared: a normalized version which allows to define ''dq''-like axes such as the electromagnetic torque depends on the only ''q''-like components of the stater current; a denormaliz ed version such as the proportionality factor between the electromagne tic torque and the current ''q''-like component is constant (does not depend on the rotor position).